A recent C-17 airdrop of humanitarian aid to Iraqi refugees on Mount Sinjar included more than 3,800 gallons of fresh water stacked aboard 40 complex container delivery systems, complete with self-deploying parachutes.

It’s a massive logistical undertaking. Unless you’re a team of Army parachute riggers, in which case it’s less than an afternoon’s work.

An 18-soldier team can put together that amount of bundles in two hours, according to a recent Army news release highlighting the work of such riggers at two unnamed U.S. Central Command bases during the ongoing aerial aid missions. The fifth airdrop, conducted Tuesday, involved four cargo planes, more than 5,000 gallons of water and upwards of 11,000 meals, ready-to-eat.

“The most challenging portion of the operation is placing these halal meals, which are MREs, on the pallets,” Spc. Jonathan Echaves said in the Monday release. “It’s like playing ‘Tetris.’ ”

U.S. aircraft have provided more than 85,000 MREs and 20,000 gallons of water to refugees in northern Iraq — thousands of Yazidis, a religious minority group, trapped atop Mount Sinjar by fighters from the Islamic State of Iraq and the Levant. Kurdish fighters have worked to free the group; it’s unclear how many remain isolated.

“It was so important we did this, because these [refugees] were starving, cut off,” Staff Sgt. Justin Wright, a loadmaster with the 816th Expeditionary Airlift Squadron, said in the release. “Having all this come together was challenging, but it was definitely worth it.”